Crystallizer



T` E. STEVENS CRYSTALLIZER Filed July '7 prr'. l0, 1923.

mento/z wamngteuens Clttozmu Patented Apr. ld', 1923.

TRUMAN E. STEVENS,

'0F OMAHA, NEBRSKA, ASSIGNOR T0 POTASH REDUCTION COMPANY, OF HOFFLAND, NEBRASKA, A CORPORATION OF'NEBRASKA.

CRYSTALLZER.

Application led July 7,

T all whom it may concern Be it known that I, TRUMAN E. STEVENS, a citizen of the United States, residing at Omaha,in the county of Douglas and State of Nebraska, have invented new anduseful lmprvemeI/its in Crystallizers, of which the following is a specification.

This invention relates to crystallizers and more particularly to that type of crystalio lizer in whichL crystallization is forced from solutions of soluble salts by means of a cooling medium.

One of the obstacles to successful operation of crystallizers of this type when used is with solutions of salts such as sodium carbonate, sodium sulphate, etc., which have the property when crystallizing of adhering' to adjacent surfaces is that the crystals of such' salts, as they form, adhere to the surface of ao the conduit carrying the cooling medium, building u a heat insulating layer which progressively decreases the cooling efficiency of said cooling medium up to the point Where it is rendered practically ineffective to 2a force further crystallization.

One of the objects of my invention is to provide a jacketed tank for carrying out the process of crystallization from solutions of soluble salts in which means is provided for 3o mechanically removing the crystals from the jacketed tank ywalls as fast as they are formed.

Another object of the invention is to pro- Vide means for lstirring the solution during the crystallization process for the purpose of maintaining uniform the density of the whole body of liquid within the tank.

My invention is hereinafter more fully described in connection with the accompany- 4.o ing drawings. Objects of a more specific nature will become apparent in the description. and the essential characteristics are summarized in the claims.

Figure 1 is a front elevation partly in e5 section of the apparatus which constitutes my invention.

Figure 2 is a perspective view of the crystal remover and agitator.

Figure Bis a top plan view of the tank shown in Figure 1 taken in a plane just helow the gears.

ln the drawing the numeral 1 represents atank having a cylindrical wall 2 and conical bottom 3. The wall 2 is surrounded by a jacket i which forms a space therebetween Serial No. 483,006.

for the reception of a cooling mediuml such as water or liquid ammonia. which is supplied by the pipe 6.

the pipe 5.and drawn 0H through A drain pipe 7 communicates with the lower part of the conical bottom 3 and is controlled by the cock 8.` The tank is mounted on suitable supports 9.

Extending transversely across the interior of the tank at the top is vthe member 10 apertured rotatable at 11 to form a bearing for the sha-ft 12. The lower end of this shaft abuts as at 13 against a similar member y14 extending transversely across the up- ,r part of the conical portion of thetank. vThe shaft 12 is hollow and forms a bearing for an inner shaft 15 the lower end of which is journalled in a recess 16 at the lower end of the conical bottom portion of the tank.

Secured to the outer shaft 12 by the cross bars 17 are a pair of brushes 18 which are arranged in scraping relation to the inner surface of thewall 2 of the tank. These brushes are composed of stiff fibers or wires 19 which are mounted in a back portion 20 and extend longitudinally of the inner cylindrical wail of the depth of the jacketed porthroughout the tank substantially tion thereof. Upon theupper end of the shaft 12 is rigidly mounted a beveled gear 21 meshing with a smaller gear 22 driven by a pulley 23 power. By

ment with the cylindrical from any desired source of means of the rotation of the ear 21 the brushes are rotated in engageside walls of the tank removing therefrom the crystals as they are formed, the bristles ofA ing sufficiently to I the brushes flexdetach any crystal masses which may adhere to said brushes.

ldithin the conical lower portion of the tank is an agitator 22 comprising a frame 23 having sloping side members 24 which are constructed to rotate in proximity to the conical inner surface of the tank. The

frame 23 is fixed to the inner shaft 15 which is rotated independently of the outer shaft 12 by driven by power.

insure a means of the train 'of gears 25 and 26 the pulley 27 from a source of rlhe object of the agitator 22 is to thorough mixing of the hot concen trated solution in the conical portion of the tank with the cooler and more dilute solu tion in the cylindrical'portion of the tank -thus maintaining the liquid in the tank This it does by density of the body of substantially uniform. throwing the concentrated solution in the conical portion againstv the inclined walls thereof by centrifugal force causing a' current of concentrated .solution to travel upwardly, replacing the spent solution adjacent the brushes. The circulation thus set up also washes the crystals away from the neighborhood of the brushes and carries them to the central partv of the cylindrical portion of .the tank where they float in the unagitated body of the solution from which they may periodically be dipped out.

In order to secure a more thorough mixing of the solution the agitator is preferably driven in an opposite direction to that of the revolving brushes.

While the inner and outer shafts 12 and 15 are here Yshown as driven through separate sets of gearing it is obvious that it would vbe within-the spirit of the invention todrive them through a single train of' "gears if desired.

It is obvious that various changes may be made in the details of construction without departing from this invention and it is therefore to b e understood that this invention is not'to be limited to the specific construction shown and described.

Having described my invention -What I claim as new and desire to secure by Letters Patent is l. In a crystallizer, a tank having a jacketed wall provided with a crystallizing surface, means for passing a cooling medium through said jacketed wall and a revolving brush having the bristles thereof engaging said crystalllzing surface to remove crystals therefrom.

2. In a crystallizer, a tank having a jacketed wall provided with a 'crystallizing surface, means for circulating a cooling mediumfthrough said jacketed Wall, a shaft journalled in said tank and a rotating brush driven by said shaft having the bristles thereof engaging said crystallizing surface.

8. In a crystallizer, a. tank. having a cylindrical jacketed portion and a. conical bottom portion, an agitator mounted within said tank comprising rotating members in said cylindrical and bottom portions respectively, said member 'in said cylindrical portion being' provided with a brush having bristles engaging the inner surface of said cylindrical portion.

4. In a crystallizer, a tank, having a cylindrical jacket'ed portion provided with a crystallizing surface and a conical bottom' portion, independently driven 'agitators rotatably mounted within said cylindrical and conical portion respectively, said` member in said cylindrical portion being provided with a brush having bristles engaging said crystallizing surface.

5. In al crystallizer, a tank having a jacketed side wall provided with a crystallizing surface and a conical bottom, a shaft journalled in said tank, an agitator mounted on the lower end of said shaft adjacent the conical bottom, a hollow'shaft journalled on the first named shaft, a. brush Vcarried by said hollow shaftengaging said crystallizingsurface and means for independently driving said shafts.

6. In a crydallizer, a tank having a cylindrical jacketed side wall provided with a crystallizing surface, and a conical bottom, a brush conforming to the shape of the crystallizing surface gagement therewith, an agitator rotatably mounted within. said conical portion and having sides conforming to the slope of said conical portion andv means for independently driving said brush and agitator.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

,TRUMAN E. STEVENS. Witnesses: l

F. A.. Groen, G. R. SrnvnNsoN.

and having bristles in en-V 

